open (one's) mouth

(redirected from opens their mouth)

open (one's) mouth

To say something, especially that which is indiscreet, boorish, or meant to be a secret. Why did you have to open your mouth about my crush on Tommy? Why couldn't you just keep it between us? You've got to make sure that he never opens his mouth about what went on here today.
See also: mouth, open
References in periodicals archive ?
ck oo mwwt "What kind of 'man' opens their mouth and talks about something when they have your number but they don't talk to you?
The mouth insert lights up when the wearer opens their mouth, providing a glowing smile, reports the Daily Mail.
But then the singer whose parents are excitedly waiting in the next room (after having sent several e-mails about how talented their prodigy is and how excited/prepared/nervous they were) steps up to the audition spot and opens their mouth.
It is bearable when Richard Burton adds a bit of class to proceedings, but burn-your-stereo-annoying when anyone opens their mouth to sing.
Again, there's a simple rule of thumb at work here: When anyone opens their mouth to sing, it's good; when anyone opens their mouth to talk, it's bad.
It's one of those frightening, well-meaning movies in which every time anyone opens their mouth, something wise and reverent comes out.